1. Field of the Invention
The present invention relates to a refrigerator and an operating method therefor, and more particularly, a refrigerator and an operating method therefor controlling the temperature of a sub storage compartment separately provided to a main body.
2. Description of the Related Art
Generally, a refrigerator generates cool air through a cooling cycle to preserve food for a period of time, and includes a freezing compartment storing food frozen below the freezing point, a refrigerating compartment storing food refrigerated above the freezing point, and a cooling system cooling the freezing compartment and the refrigerating compartment.
Korean Patent Publication No. 2004-49591 discloses a refrigerator provided with an independent compartment, the temperature of which is independently controlled with respect to a refrigerating compartment and a freezing compartment. The refrigerator includes a casing forming the independent compartment, such as a temperature converting compartment, a cool air flowing hole formed in the casing to be connected with the freezing compartment, a heater heating an inside of the casing, and a controller controlling the heater. If the independent compartment needs to have a temperature higher than the refrigerating compartment, the controller operates the heater so that the temperature of the independent compartment increases. If the independent compartment needs to have a temperature lower than the refrigerating compartment, a fan provided in the refrigerating compartment or the freezing compartment is operated to supply cool air inside the refrigerating compartment or the freezing compartment to the independent compartment through the cool air flowing hole so that the temperature of the independent compartment decreases.
However, in the conventional refrigerator, cool air and heat are directly supplied into the independent compartment to be contacted to food stored therein, and accordingly, moisture for the food is evaporated, which thereby deteriorates freshness of the food.
FIG. 10 illustrates the temperature variation of a sub storage compartment (not shown) according to a conventional operating method for a conventional refrigerator (not shown). Referring to FIG. 10, a sub storage compartment according to a conventional operating method for a conventional refrigerator is forcedly heated to reach an upper limit temperature, and then the sub storage compartment is forcedly cooled to reach a lower limit temperature.
Also, in the case that the temperature of the independent compartment needs to be decreased after the heater is operated to increase the temperature thereof, the fan of the refrigerating compartment or the freezing compartment needs to be operated, thereby increasing power consumption.
Also, in the case that the temperature of the independent compartment needs be increased after cool air is supplied to decrease the temperature thereof, the heater needs to be operated, thereby increasing power consumption.
Also, in the case that the temperature of the independent compartment needs to be increased while the refrigerating compartment or the freezing compartment is cooled, the heater and the fan must be simultaneously operated, thereby deteriorating energy efficiency.